Um.... Why is it so hard to believe that the McClelland tang might not be the result of an additive?
Sure, all tobaccos are cased, but I have no reason to believe the trademark smell/taste isn't the byproduct of aging, fermented vas that haven't been processed in the same ways that other blenders to (steam, sugar, etc,). Especially since the folks at McClelland roundly deny using vinegar or anything else that causes the McKetchup experience. True, they could be lying through their teeth, but that's a heavy accusation to lay at their feet (I've never heard of anything but point blank denials being attributed to McC officials, so if anyone has heard them say otherwise feel free to correct me).
For the record, I HAVE encountered the exact same taste/smell from other blenders who use American Virginias -- C&D. It only happened to a couple of batches of their blending Virginias, but it DID happen. After a bit of aging, the previously normal smelling Vas developed that familiar ketchupy thing. I was surprised, to say the least!
I could be wrong, of course. Heck, all of us could be wrong. But the fact is that few - if any -- of us have a lot of firsthand experience in the processes used to prepare Vas. The fact that ive only encountered the ketchupy thing in American grown Vas (unlike the Gawiths or most other European blenders) leads me to suspect that McClelland might be telling the truth.